Personality can be defined in terms of enduring individual differences in emotional, interpersonal, experiential, and motivational styles. The five factors of Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness provide a comprehensive taxonomy of personality traits for the description of personality in aging men and women. Two studies examined issues in personality structure. In the first, the five-factor structure of the NEO-PI-R was shown to be replicable in Chinese and Japanese data; in the second, positive and negative valence were located in the five-factor space.